Diet can have a clear effect on testosterone level, but it is less likely to be noticed in younger men, whose testosterone levels are high anyway. However, testosterone levels decline naturally as men become older, so the effects of diet on testosterone can be more meaningful as men age into their forties and beyond.
A man’s testosterone level drops by about 10% per decade. Symptoms of this decline can include a lower sexdrive, impaired sexual function, less energy and drive, reduced muscle mass and physical strength, and increased body fat, especially around the waist. The increase in erectile dysfunction with age is somewhat due to decreasing testosterone level. It can also be related to blood flow restrictions to the penis caused by disease processes. For example erectile dysfunction is much higher among diabetics than among healthy men.
A 1997 scientific journal article “Testosterone and cortisol in relationship to dietary nutrients and resistance exercise” by Volek et al. of Penn State University, strongly linked a man’s testosterone level to his diet. Among the male subjects studied, when the following were higher in the diet, testosterone tended to be lower:
- protein intake as a percent of diet
- ratio of polyunsaturated to saturated fat intake
- ratio of protein to carbohydrate intake
In contrast, when the following were higher in the diet, testosterone tended to be higher as well:
- percentage of fat in the diet
- saturated fat intake per unit body weight
- monounsaturated fat intake per unit body weight
This study also showed a weak negative effect of dietary fiber intake on testosterone level. Since other studies found this as well, excess fiber intake may be considered a risk factor for lowered testosterone levels.
These results are important for several reasons. First, they highlight a tradeoff between eating for health and longevity and eating to maintain male sexuality. A diet high in saturated fats, while promoting testosterone production, is plainly contradictory to the recommendations of the American Heart Association, which promotes a lower fat diet. Also, the study contradicts the commonly-accepted notion that eating more protein makes men more masculine. Body builders often eat great quantities of low-fat protein yet have enormous muscles. Their high-protein, low-fat diets might reduce their natural testosterone levels as a result, but some of them make it up by taking steroids or testosterone supplements via injection, pill, or skin-penetrating cream. However, in addition to several other possible health effects, testosterone or steroid supplementation results in shrinking of the testicles and reduction in the body’s natural testosterone production. It can also cause infertility. Thus, maintaining and enhancing one’s testosterone level naturally is clearly the preferred alternative. Even though the study mentioned above revealed that some foods good for raising and maintaining one’s testosterone level raise the risk of heart disease, it is possible to select foods that are not detrimental to one’s health but still facilitate the body’s testosterone production.
It isn’t necessary to eat a low protein diet in order to promote testosterone production. A careful examination of Volek’s article shows that only the men who ate extremely high quantities of protein and who had exceptionally high protein-to-carbohydrate intake ratios had lower testosterone levels. These individuals had great influence on the statistical association. Without those subjects, the apparent relationship of protein intake and protein-to-carbohydrate ratio to testosterone level disappears. So, a man who ingests a healthy but not excessive quantity of protein needn‘t be concerned. Daily protein consumption of 2 grams per kilogram body weight (0.9 grams per pound body weight) supplies plenty of protein for muscle growth and repair, as well as healthy body function, without risking suppression of testosterone production.
As to the positive effect of saturated fat intake on testosterone levels, one may ask whether it‘s worth risking heart health by eating a lot of saturated fats such as those found in fatty meats and full-fat dairy products in order to enhance testosterone production. Fortunately, this is neither necessary nor prudent. Monounsaturated fat, as found in olive or flaxseed oil and nuts, has the same positive effect on testosterone level as saturated fat. So a man needn’t load up on fatty meats, full-fat dairy products, or tropical oils in order to maximize his testosterone. Liberal use of olive oil in cooking provides plenty of monounsaturated fat. And a diet high in this good fat also promotes a healthy HDL cholesterol level which helps prevent heart disease. In contrast, a high saturated-fat diet can lead to arterial disease and directly cause erectile dysfunction by reducing blood flow to the penis.
Another study published in 2000 examined the relationship between diet and SHBG, and found that "diets low in protein in elderly men [40-70 years old] may lead to elevated SHBG levels and decreased testosterone availability. The decrease in bioavailable testosterone can then result in declines in sexual function and muscle and red cell mass, and contribute to the loss of bone density."
If your purpose is to maximize testosterone levels to help increase muscle tissue, your diet should be approximately 55 percent carbohydrates, 15 percent protein and 30 percent fats. The danger is that a diet high in fats may increase your risk of developing cardiovascular disease. If you prefer the safer and more conservative approach, you can choose the alternative arrangement as 50 percent carbs, 30 percent protein and 20 percent fats. Both diets are in line with the Kappas study, which found that men given a high carb diet showed higher testosterone levels than those given high protein diets.
Balanced diet is a key to the healthy life. Some modern extremists views on the dietary restrictions might be trendy and appealing, but are quite challenging, and in some cases, even dangerous to your health. In terms of testosterone, Vegetarians will experience a 14% reduction in testosterone levels, and vegans – even higher losses. And your body really needs some saturated fat as well in order to produce optimal levels of testosterone.
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